In many order filling operations, orders are filled for quantities of full cases or cartons of items. In such an operation, it is only necessary to gather the required number of cases together, apply shipping labels to the cases, and transfer the cases to a shipping dock. A supplier of goods to merchants for resale might operate in such a manner.
In contrast, consumer orders for merchandise often consist of one or several each of a plurality of items, that is, less than a full case of items. In processing such an order, it is necessary to count out the required number of items from a case thereof, group the various items together, send the group to a packing station, and from there to a shipping dock. As the number of different items carried by such supplier increases and as the volume of orders increases, it is difficult to run the operation efficiently if a large amount of human handling of the orders is required.
Efforts to reduce the amount of human activity in the filling of orders include the use of conveyors, receptacles or bins on the conveyors to group the items of an order, coded markings on the bins, sensors to read the coded markings, timers in combination with limit type switches, and mechanical and electrical analogs of order filling systems including digital computers.